Monday, October 08, 2007

Another Geo-Engineering Scheme

The oceans, which cover more than 70% of the Earth’s surface, are a promising place to seek a regulating influence. One approach would be to use free-floating or tethered vertical pipes to increase the mixing of nutrient-rich waters below the thermocline with the relatively barren waters at the ocean surface. (We acknowledge advice from Armand Neukermans on engineering aspects of the pipes.) Water pumped up pipes — say, 100 to 200 metres long, 10 metres in diameter and with a one-way flap valve at the lower end for pumping by wave movement — would fertilize algae in the surface waters and encourage them to bloom. This would pump down carbon dioxide and produce dimethyl sulphide, the precursor of nuclei that form sunlight-reflecting clouds.From an engineering perspective this is probably not feasible, but even if it was, the effect would be the exact opposite of that hoped for: more CO2 would be released into the atmosphere than would be absorbed by the algae blooms. The simpler of the two explanations of why this should be so is:

“The concept is flawed,” says Scott Doney, a marine chemist at WHOI. He says it neglects the fact that deeper waters with high nutrients also generally contain a lot of dissolved inorganic carbon, including dissolved CO2. Bringing these waters to the lower pressures of the surface would result in the CO2 bubbling out into the air. So contrary to the desired effect, the scheme could result in a net ‘outgassing’ of CO2...Ah well, maybe we can live in polar cities, and in any case, nobody has shot down my Carbopult(TM) idea.

"Geo-engineering" sounds like a bland and technical term but it isactually a Messianic movement to save the world from global warming,through dust and iron and thousands of tiny mirrors in space. It isalso the last green taboo.

Environmentalists instinctively do not want to discuss it. The widerpublic instinctively thinks it is mad. But now, the taboo has beenbreached. James Lovelock, one of the founding fathers of modernenvironmentalism, proposed a way to slash global warming withoutcutting back on a single fossil fuel.

"Geo-engineers" believe man should consciously change the planet'senvironment, using technology, to counter the effects of globalwarming.

Is humanity so resistant to change that we will tamper with thebiosphere's workings to construct a "Frankensphere"; rather thanreducing population, consumption and emissions?

It is being widely suggested that humanity can "geo-engineer" a globalsolution to climate change; that is, modify the Earth's biosphere at aplanetary scale. Many methods are suggested. Most include eitherreflecting additional solar radiation away from the Earth, or usingthe ocean to store more carbon.

Endless treaties to cut carbon emissions and halt global warming have failed to turn the tide of pollution. Now scientists want to intervene on a planetary scale, changing the very nature of our seas and skies. Ahead of a major report on 'geo-engineering' we reveal the six big ideas that could change the face of the Earth

Robin McKie and Juliette JowitSunday October 7, 2007The Observer

They are the ultimate technological fixes: schemes that will span our planet and involve scientists in reshaping our world to save it from global warming. Yet only a few years ago, such projects - giant space mirrors, flotillas of artificial cloud makers and ocean fertilisation programmes - were dismissed as the stuff of science fiction.Today many engineers and researchers - fearful of the rate at which our planet is warming - say geo-engineering projects are now mankind's only hope of saving itself from the impact of climate change. A major report and a new exhibition at the Science Museum starting next week will resurrect the debate.